On This Day . . .

Close-ups From Space

July 15, 1965: Mariner IV Sends First Pictures of Mars

Mariner 4 was the first spacecraft to fly by Mars, and the first to return close-up images of the Red Planet.

Its blurry views of craters and bare ground led some scientists to think that Mars is similar to the moon. It squashed some views that Mars was a haven for life.

Later missions showed that Mars is actually quite different from the moon, with an active weather system and a much wetter past.

Life on Mars

It’s hard to pinpoint when the discussions of life on Mars began in earnest, but astronomers’ observations of the Red Planet in the late 1800s and early 1900s helped spur a wave of interest.

Percival Lowell, an American businessman and astronomer (the choice of the name Pluto and its symbol were partly influenced by his initials PL) spent years studying Mars from an observatory he financed at Flagstaff, Ariz. He made sketches of the surface and published the results. Telescope resolution wasn’t all that great at the time, but Lowell felt that he was seeing canals on the Red Planet that were possibly built by intelligent beings.

Percival Lowell with his telescoipe

As his observations became public, interest in Mars was soaring. Dozens of books, movies and television programs portrayed different views of civilization, ranging from H.G. Wells’ “War of the Words” and Martian aliens in episodes of “The Twilight Zone” to Marvin the Martian on “Looney Tunes.”

Getting to Mars

These were the early days of space exploration with a high rate of failure as NASA and the Soviet Union each tested new technology. As such, NASA elected to send two spacecraft to Mars around the same time – Mariner 3 and Mariner 4. This success had worked previously with Mariner 1 and Mariner 2’s voyages to Venus; while Mariner 1 failed, Mariner 2 successfully sent back information.

Mariner 3 launched Nov. 5, 1964. It made it into space successfully, but a fairing intended to protect the spacecraft during launch jammed instead of coming off as planned. This doomed the spacecraft before the mission could get started.

This left only Mariner 4 to carry out the mission. NASA and its contractors hastily redesigned the nose fairing in the three weeks before its launch, and cheered its success when the spacecraft successfully headed for Mars on Nov. 28. The 574-pound (260 kilogram) spacecraft spent more than seven months cruising to the Red Planet.

Mariner’s 1st picture sent

Close Encounter

Mariner 4 spent just 25 minutes doing observations of Mars as it cruised by on July 14, 1965. In that brief time, it took 21 full pictures that it beamed back to Earth the next day. The spacecraft’s views would be the first ones beamed back from another planet.

After the pictures came back, they showed no canals or any obvious signs of life at all. Although blurry by today’s standards, the images were clear enough to reveal a heavily cratered surface. Scientists said it appeared Mars was more similar to the moon than to Earth.

Reaction to Mariner 4’s results

There was disappointment among some scientists, and the public alike. “The New York Times” remarked that Mars is “probably a dead planet.”

NASA’s continued exploration of the Red Planet has revealed a much less barren surface than what Mariner 4 suggested. The Spirit, Opportunity and Curiosity rovers have all found evidence of past water on the surface, with their “ground truth” observations supplemented by large-scale views of the planet from orbiting spacecraft.